1. Field of the Invention
This invention relates to an apparatus and a method of processing semen and allowing its associated spermatozoa to become segregated to permit subsequent selection thereof, to increase the number of motile and morphological samples to be recovered therefrom.
2. Prior Art
A number of methods have been proposed for the processing of semen so as to increase its quality and quantity of spermatozoa population of a given semen sample. With improved quality and quantity of such spermatozoa, the probability of success of Artificial Insemination (AI), In Vitro Fertilization (IVF), Intracytoplasmic Sperm Injection (ICSI), and other related Assisted Reproductive Clinical Technologies (ARTs), may be improved. Some of the methodologies include washing and storage of the spermatozoa in media, and the "swim-up" procedure, a technique that takes advantage of the swimming abilities of a small percentage of spermatozoa within a given sperm population.
One attempt at the improvement of the collection of spermatozoa is shown in U.S. Pat. No. 3,894,529 to Shrimpton, entitled, "Method and Means For Controlling the Sex of Mammalian Offspring And Product Therefor". This patent discloses a method of separating X and Y sperm so as to control the sex of a desired offspring by inseminating an egg with an X or a Y sperm. The sperm is separated by applying a buoyant force to a mixture of sperm in the nutrient media so that the separation occurs according to the density of the sperm.
U.S. Pat. No. 4,759,344 To Wang, entitled, "Wang's Tubules For Sperm Preparations Used For IVF-ET-GIFT and Artificial Inseminations", discloses a method and an apparatus for separating sperm having the greatest motility. The sperm are allowed to swim upward in a column, where they may be collected to provide the strongest samples for insemination.
Processes such as these are relatively simple, however they are often inefficient and maybe susceptible to technician error and/or to laboratory variations.
Further, none of these techniques allow the use of the "swim-up/swim-down" principle nor do they permit selectivity based on the various characteristics such progressive motility, morphological characteristics, X or Y bearing sperm ratio and the like.
It is an object of the present invention, to provide a method in apparatus for the selection of a desired spermatozoa population from a given semen sample, to maximize the probability of success when that semen sample is utilized for artificial insemination, in vitro fertilization, intracytoplasmic sperm injection, and other related assisted reproductive clinical technologies.
It is yet a further object of the present invention, to provide a method and an apparatus that will minimize the likelihood of technical error and laboratory variations, and permit the selection of a particular population of spermatozoa.
It is yet still a further object of the present invention, to provide a method in apparatus to take advantage of the "swim-up/swim-down" principle and to permit the entrapment of various classifications of spermatozoa based on their various characteristics such as progressive motility, morphological characteristics, X or Y bearing sperm ratio and the like.